Other mistake: Towards the end when Dennis Hopper is on the subway train with Sandra Bullock, he has a gun in one hand and the detonator in the other. However, when the camera cuts to a close-up of him handcuffing Sandra to the pole, both hands are empty. If he took his hand off the detonator, the explosives attached to Sandra should've exploded, but they didn't. In the next shot, both items are back in his hand. (01:39:50)
Other mistake: The kids dare each other in a decrepit water tower which is mysterious in a number of ways: 1) Draining the water causes a powerful vortex, but the water level is not going down. 2) No one seems to work the bottom valve, but the vortex comes and goes. 3) It is absolutely impossible that anyone could swim through such a vortex, but Stu does. 4) The rotten roof breaks under the weight of little Billy (the ice-cream excess?) but carries his brother who weighs about 4 times as much. (01:27:00)NancyFelix
Other mistake: The first plane to explode has a very neat symmetrical blast originating from underneath the plane - which is in fact wrong given that only one charge was placed on the side of the plane. The plane would be badly damaged and probably jack knife through the side of the hangar instead.
Other mistake: In the brief scene in which Nicholas Andre and J.P. Shay are talking about the killing of the owl at the preservation society ball, if you look very closely out the very bottom of the window, at the very end of the short scene (right after Andre says, "Their guys aren't just anybody, they're good"), you can catch a brief glimpse of part of the box containing the victim who is trying to escape (this box was completely excluded from the film).
Other mistake: When Jackson and O'Neil are captured and taken before Ra, the guards hit their knees with their staff weapons to make them kneel. Jackson's guard does it right, but O'Neil's misses him completely.
Other mistake: I know most goons in movies are bad shots, but this is stupid. There are at least 20 Bison Troops in the room. There is one Guile. The guards have machine guns, while Guile has a handgun, with only 1 or 2 clips. Yet these troopers all miss him, even the ones on higher levels of the base, which give them a far better view of Guile.